Electrical connector



Nov. 12, 1968 D. N. BUSHEY ELECTRICAL CONNECTOR 2 Sheets-Sheet 1 Filed March 13, 1967 Nov. 12, 1968 D. N. BUSHEY 3,411,130

ELECTRI CAL CONNECTOR Filed March 13, 1967 2 Sheets-Sheet 2 ABSTRACT OF THE DISCLOSURE A separable electrical connector comprised of a pair United States Patent of housing assemblies are arranged to be mounted in the sides of hermetically sealed cans containing electronic modules. The housing assemblies include a series of telescopically interengageable contacts with each contact being connected to a lead wire which passes from the obverse face of the housing to the reverse face through a slot in the bottom of a well into which a potting compound is put for preserving the hermetic seal.

Background of the invention This invention relates in general to electrical connectors, and more particularly to separable connectors for encased, sealed electronic modules.

In some modular electronic systems, the modules are separably connected and contained in their own casings, and may, in the case of a transceiver, for example, be independently active units. Frequently, such casings Will be well sealed to meet rugged environmental specifications. Under these circumstances the connector, especially where the contacts are exposed when the modules are disconnected, must attain to unusually high standards.

Summary of the invention Accordingly the present invention has as objectives to provide a system for connecting sealed modular electrical units wherein the contact elements may be exposed to the weather, are self-cleansing under rugged conditions of use, and interconnect with internal wiring of the units to preserve the integrity of the seal of units.

Other objects and attainments of the present invention will become apparent to those skilled in the art upon a reading of the following detailed description when taken in conjunction with the drawings.

Brief description of the drawings FIGURE 1 is a perspective view of one part of a bipartite connector constructed and arranged in accordance with the present invention;

FIGURE 1a is a perspective view of an electrical contact of the connector part of FIGURE 1;

FIGURE 2 is a perspective view of the other part of the bipartite connector with its contact being shown in perspective in FIGURE 2a;

FIGURE 3 is a sectional view taken along lines 33 of FIGURE 1, except that the contact and lead wire are shown in full side elevation;

FIGURE 4 is a fragmentary sectional view taken along lines 44 of FIGURE 3;

FIGURE 5 is a sectional view taken along lines 5--5 of FIGURE 2, except that the contact and lead wire are shown in full side elevation;

FIGURE 6 is a fragmentary sectional view taken along lines 66 of FIGURE 5;

FIGURE 7 is a fragmentary side view of a pair of modular units in connected relation to illustrate the manner of mounting the connector of FIGURES 1 and 2; and

3,411,130 Patented Nov. 12, 1968 "ice FIGURE 8 is a sectional view taken along lines 88 of FIGURE 7.

Description of the preferred embodiment In the embodiment of the invention shown in the drawings, the separable connector is comprised of a blade contact housing assembly and a receptacle contact housing assembly, as shown in FIGURES l and 2 respectively'. Each assembly includes an insulating housing and an appropriate number of metallic electrical contacts to the end of interconnecting a pair of electrical units to be described in connection with FIGURES 7 and 8.

As shown in FIGURES l, 3 and 4 the blade contact housing assembly includes a generally rectangular insulating housing 2 preferably of a moldable synthetic plastic material such as a glass filled polycarbonate which is fairly hard, yet not brittle. A plate 4 forms the base of housing 2 and provides the means by which it is mounted on the associated electronic unit, apertures 6 being bolt holes suitably arranged for the mounting purpose. Centrally located on the obverse face of mounting plate 4 is a block 8 supporting on and along its raised surface 10 a series of blade contacts 12. An elongated slot 14 extends adjacent and generally parallel to the rear or trailing side 16 of block 8 to serve as the means for communicating between the obverse and reverse faces of mounting plate 4. Wall portions 18 upstand from plate 4 to about two-thirds the height of block 8, and continuously extend from one end of block side 16 to the other and around slot 14 to provide a well 19 to contain a potting and sealing compound as will be explained. Wall portions 18 smoothly merge with block 8 to present, in plan, a generally rectangular perimeter.

Advantageously the contacts of the present invention are stamped and formed from sheet metal and have a wire attaching means of a form suitable for use of the crimping technique disclosed, for example, in Macy Patent No. 2,600,012. The contacts may terminate otherwise, of course, such as by a solder tag, depending upon the conditions of use. Contact 12, as particularly shown in FIG- URE 1a, is thus a flat elongated blade arranged to be set edgewise across surface 10, the blade having a central depending locating and stabilizing tab 20 projecting into recess 22 of block 8 and two depending end legs 24 and 26 which connect with outwardly extending shanks 28 and 30 respectively. In the illustrative embodiment, at the end of shank 28 is a wire attaching ferrule 32 having upstanding ears arranged to be wrapped and compressed onto the bared end of lead wires 34 as shown in FIGURES 1 and 3. Intermediate its length shank 30 is twisted so that the side edges of a concavely bowed locking tab 36 are symmetrically disposed laterally of the longitudinal axis of the contact blade. A series of channels 38 extend inwardly of the leading side 40 and have a width snugly to receive locking tab 36, thereby lightly to hold the contacts in place initially. An anvil like projection 42 on the bottom of the channel is disposed so that tab 36 initially rests upon it, and against which tab 36 can be partially straightened by any suitable tool, thereupon the side edges of the tab dig into the side walls of the channel, as best shown in FIGURE 4, to anchor one end of contact 12 to the housing.

Further to stabilize contacts 12 on the housing a series of slots 44 preferably traverse raised surface 10 whereby snugly to receive the lower edge of blade 12 and leg 24.

As thus constructed, contact blades 12 are crimped to lead wires 34, passed through slot 14, and securely set edgewise in a parallel arr-ay across the face of block 8 with depending legs 24 and 26 disposing ferrule 32 and locking tab 36 in the bottom of well 19 and channel 38 respectively. Any suitable potting compound 46, FIG- URE 3, preferably of an epoxy nature, then may be put into well 19 to cover ferrules 32, the ends of lead wires 34, and to close slot 14 in a fluid-tight seal.

The receptacle contact housing assembly as shown in FIGURES 2, 2a, 5 and 6 is generally similar to the blade contact housing assembly, and thus includes housing 20 comprised of a mounting plate 4a with bolt holes 6a. Centrally located block 8a has surface 10a raised from the obverse side of the mounting plate to support a series of contacts 12a in a parallel array and recessed in channels 44a. Slot 14a running parallel to the rear side 16a of block 8a is of sufficient width to pass contacts 12a and the ends of lead wires 34a from the reverse side to the obverse face of mounting plate 4a. Wall portions 18a likewise serve to define a well 19:: into which potting compound 46a may be put thereby sealing slot 14a and covering the ends of the lead wires and contacts.

Contacts 120, being the receptacle part of the contact assembly, as especially seen in FIGURE 20, comprise a central channel 50 open at its ends and arranged to receive blade 12 in endwise telescopic relation. At a plurality of intermediate positions along the length of the channel, the base and portions of the side walls are removed to define opposed pairs of sidewall portions which are curved or bowed inwardly toward each other to form contact nodes 52, the opposed nodes being spaced less than the thickness of blade 12. Preferably contacts 12a are formed by stamping techniques from thin and resilient sheet metal, such as phosphorous-bronze, whereby after telescoping the contacts the pairs of contact nodes 52 firmly press against opposite sides of the blade positioned therebetween to insure multiple points of good electrical engagement. In this connection contacts 12 and 12a preferably will be plated with a non-corroding metal since they are external contacts exposed to adverse weather conditions.

Shank 30a at the leading end of contact 12a terminates in a convexly bowed tab 36a which, when undeformed, is easily received in channel 44a. Tab 36a, being relatively thin, is more easily deformed towards a straightened condition, by any suitable forming tool applied to the tab whereby to force its edges into the sidewalls of the channel, as best shown in FIGURE 6, locking the end of the contact securely in position. Wire attaching ferrule 32a, after being crimped onto the end of wire 34a, normally is wider than it is high in the direction of crimping. To obtain maximum electrical Spacing between adjacent contacts preferably the ferrule is laid in well 19a on its side. Thus shank 28a is twisted in the forming operation of contact 12a.

With contacts 12a snugly received and recessed in channels 44a, and contacts 12 standing edgewise along surface 10 in grooves 44, it can be appreciated that movement of housings 2 and 2a along one another in a manner to slide surface 10 across and along surface 10a, the leading end of contact blade 12 is caused to enter into channel 50 of contact 12a and further to move in telescoping relation until the ultimate position of contact with blade 12 is reached, which is when blade 12 is substantially centrally disposed along contact 12a. To constrain the housings to such movement, the cans 60 and 60a fragmentarily shown in FIGURES 7 and 8 are provided with double tongue and groove elements 62-64 and 62a-64a on either side of mounting openings 66 and 66a respectively. Opening 66 is of a. size snugly to receive block 8 as extended by wall portions 18 when plate 4 is abutted at its margins against the inside of can 60 and secured thereto as by bolts 68. Plate 4a is similarly mounted adjacent opening 66a, but in both cases for protection of the contact elements the sidewalls of the mounting openings, as extended by the interlocking tongue and groove elements 62-64 and 62a-64a, are at least as high as blocks 8 and 8a including the projection of contacts 12, see FIGURE 8. As thus constructed and arranged, the obverse face of each connector housing is recessed in a well in the side of a can which houses the associated electrical gear, and the reverse face of the connector housing is directed interiorly of the can whereby the lead wires 34-34a mayinterconnect with the electrical components of the electrical gear. The hermetic nature of the cans is thus preserved, and to this end, where necessary, a waterproofing grease of suitable composition may be applied to the margins of plates 4-4a.

What is claimed is:

1. In an electrical connector for coupling two sets of leads, an insulating member having a raised surface on an obverse face, a well adjacent said surface having an opening through to the reverse face, a set of contacts on said surface, each contacthaving a shank portion extending within said well and a connecting portion'adjacent' said opening for attachment to a lead directed to saidopening, said well having sidewalls arranged to confine a sealing compound introduced therein for closing the opening.

2. A connector according "to claim 1 wherein said connecting portion lies along the bottom of said well for attachment to a lead extending through said opening and into said well.

3. A connector according to claim 1 wherein said contact has a shank terminating in a bowed tab force-fitted between opposed walls of said member to anchor the contact at one end.

4. A connector according to claim 3 wherein said tab is upwardly bowed, and partially flattened to drive its side edges into said walls.

5. A connector according to claim 3 wherein said tab is downwardly bowed, and substantially flattened to drive its side edges into said walls. t

6. A connector according to claim 2 wherein said well is defined by an upstanding wall continuous with the sides of said raised surface to define therewith a block-like portion for fitting within an opening in a casing. 4

7. A connector according to claim 6 wherein said wall has a height substantially less than said raised surface.

8. An electrical connector for coupling the two sets of leads of electrical modules contained in casings having sidewall mounting openings, comprising a pair of insulating members each having a mounting plate, a central block portion on said plate providing a raised surface, wall portions upstanding on said plate and connecting with said block portion, margins of said plate being arranged to engage the respective casing upon fitting said block portion in a mounting opening to present the raised surface of one member externally of the casing for sliding along the raised surface of the other member, a slot in the bottom of said well opening through the member to the interior of the casing, a set of elongated parallel contacts arrayed across said raised surface, each contact having a shank at each end of a contact section, one shank UNITED STATES PATENTS 2,329,471 9/1943 King 339-220 3,091,750 .5/1963 Long et al. 339-94 X 3,239,794 3/1966 Roelsgaard et 'al. 339-94-X 3,245,024 4/1966 Evans 339-220 X MARVIN A. CHAMPION, Primary Examiner.

J. R. MOSES, Assistant Examiner. 

